PROJECT ABSTRACT (OVERALL COMPONENT) The overall goal of ESSENCE (Enabling translation of Science to Service to ENhance Depression CarE) is to bridge the science to service gap and strengthen an existing collaborative network of institutions in South Asia bound together by the NIMH supported SHARE Hub (the South Asian Hub for Advocacy, Research and Education on mental health) for International Mental Health Research, by generating knowledge on cost-effective implementation approaches for scaling up of evidence based interventions for mental disorders, and building capacity in a range of key stakeholders to enhance the conduct of implementation research, the dissemination of its findings, and the uptake of this evidence in policy and programs, ultimately resulting in reduction of treatment gap for mental disorders. The Scale Up component will primarily contribute to knowledge generation. The research in the Scale up component consists of two complementary, sequential randomized controlled trials, conducted over the five years. The first trial (the ?Training trial?) will test two approaches for online training interventions compared with traditional face to face training for Non-Specialists Health Workers to deliver the Healthy Activity Program, an evidence based brief psychological treatment for depression in primary care attenders. This will be followed by a three-arm, cluster randomized controlled trial (the ?Implementation trial?) which will evaluate the impact of progressively incremental resource-intensive implementation support strategies to integrate collaborative care to deliver evidence based clinical treatments for depression in primary care on patient outcomes, service use outcomes and implementation fidelity. The Capacity Building component aims to strengthen the capacity in the four South Asian countries to conduct implementation research in mental health, disseminate the findings to facilitate knowledge exchange, and promote the uptake of research findings to facilitate evidence-based mental health policy making and program planning. The Administrative Core will evolve from the existing administrative infrastructure of SHARE and will take responsibility for the overall administration, coordination, management and monitoring of all components, ensuring that the milestones are being met, that there is effective coordination between the components, networking with other initiatives in the regions, and appropriate research uptake of program outputs and outcomes. We envisage strong synergies between all the three components in a variety of ways, for example ensuring that the findings generated in Scale Up component will be disseminated by professionals who are offered mentored fellowships leading to knowledge exchange while Capacity Building of policy makers and program managers concerned with the Scale Up component will aim to enhance knowledge uptake. This will be ably supported by the Administrative Core laying the foundation of a long-term South Asian Mental Health Implementation Science Hub.